This is my column this week in the New Zealand Herald, which is published in the digital edition every Thursday…

Last week’s horrific mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida set off what is now a sadly predictable flurry of public responses.

Thoughts and prayers, followed by calls for gun control, while the White House once more looked to blame “mental illness” for the tragic series of events.

But is the terrible trend of mass shootings and gun violence in the US associated with mental illness? Are the individuals who carry out these deeds mad, or just bad?

We’re certainly told it’s “crazy”, in the colloquial sense of the word. It certainly is both hard to understand, and terrifying that young people would turn up to school and gun down fellow students and teachers. Common sense would have us believe they must be mad, right?

Common sense generally has a lot to answer for, and in this case, it is plain wrong.

Shootings like these are alarming and horrific, which also makes them newsworthy. We can’t help but hear about them, indeed the whole world hears about them.

“Only about 4 per cent of interpersonal violence in the United States can be attributed to mental illness, the study authors conclude, yet close to 40 per cent of news stories about mental illness connect it to violent behaviour that harms other people.”

This is stigma in action, plain and simple. Discrimination that is further propagated by government officials looking for a scapegoat to avoid talking about the real issue: gun control.

Firstly, when we look specifically at mass shootings (defined by three or more victims), only 1 per cent of incidents involve a shooter with a serious mental illness. Less than 3 per cent of all gun-related homicides involve a shooter with a mental health history.

In fact, people with a mental health diagnosis are significantly less likely than the general population to commit any kind of violent crime, including gun-related homicide.

However, there is a link between guns, violence, and mental health – and one that no one talks about. Mental illness does, in fact, cause the majority of firearm deaths in the US: by suicide.